EP0037353A1 - Process for the etherification of phenols - Google Patents

Process for the etherification of phenols Download PDF

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Publication number
EP0037353A1
EP0037353A1 EP81420047A EP81420047A EP0037353A1 EP 0037353 A1 EP0037353 A1 EP 0037353A1 EP 81420047 A EP81420047 A EP 81420047A EP 81420047 A EP81420047 A EP 81420047A EP 0037353 A1 EP0037353 A1 EP 0037353A1
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Prior art keywords
dihydroxy
radical
carbon atoms
benzene
naphthalene
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German (de)
French (fr)
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EP0037353B1 (en
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Serge Ratton
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Rhone Poulenc Specialites Chimiques
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Rhone Poulenc Specialites Chimiques
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    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
    • C07C45/61—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups
    • C07C45/67—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups by isomerisation; by change of size of the carbon skeleton
    • C07C45/68—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups by isomerisation; by change of size of the carbon skeleton by increase in the number of carbon atoms
    • C07C45/70—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups by isomerisation; by change of size of the carbon skeleton by increase in the number of carbon atoms by reaction with functional groups containing oxygen only in singly bound form
    • C07C45/71—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by reactions not involving the formation of >C = O groups by isomerisation; by change of size of the carbon skeleton by increase in the number of carbon atoms by reaction with functional groups containing oxygen only in singly bound form being hydroxy groups
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C41/00—Preparation of ethers; Preparation of compounds having groups, groups or groups
    • C07C41/01—Preparation of ethers
    • C07C41/09—Preparation of ethers by dehydration of compounds containing hydroxy groups

Definitions

  • the present invention relates to a new process for the selective etherification of a phenolic function of compounds which may contain several.
  • This method can make it possible to selectively obtain a monoether when stoichiometric quantities of reagents are used.
  • the reagents used are expensive and, in addition, the reaction gives rise to mineral salts posing problems of corrosion of the equipment and toxicity of the effluents.
  • French patent application n ° 74-18.172 (published under number 2.231.649) describes a process for the etherification of phenolic compounds, having one or more hydroxyl groups, with a saturated aliphatic alcohol having 1 to 4 carbon atoms or a ester of such an alcohol and of a saturated aliphatic carboxylic acid, in the presence of an aliphatic tertiary amine or of a chloride, a sulfate or a carboxylate of such an amine.
  • this process is applied to a dihydroxylated phenolic compound, a mixture of mono- and diethers is obtained.
  • French patent application No. 77-37263 (published under No. 2,373,506) describes a process for the preparation of alkyl and aryl oxides by reaction, in the presence of strongly acid cation exchange resins, d an aromatic compound hydroxylated with an aliphatic alcohol, this process being characterized in that one operates with at least 3 moles of aromatic compound hydroxylated per mole of aliphatic alcohol.
  • the process implementation temperature is preferably between 110 ° C and 130 ° C. This process makes it possible to selectively obtain the monoether from a polyphenol.
  • the main disadvantage of such a process lies in the high cost of the resins used as catalyst and in their sensitivity to heat which risks causing their degradation.
  • a new process has now been found, constituting the present invention, which uses inexpensive reagents and which leads to the selective etherification of a phenolic function of a compound which may contain several.
  • Etherification is said to be selective because during the implementation of the process according to the invention, a single phenolic function is etherified, when said phenolic compound comprises several of them on the same aromatic cycle.
  • the invention can also be presented as a process for the preparation of phenol monoether by reaction of a compound of general formula (I) with an etherification agent chosen from the group consisting of alkyl carboxylates, the linear alkyl radical. or branched having 1 to 6 carbon atoms, the alkenyl carboxylates, the linear or branched alkenyl radical having 3 to 6 carbon atoms and the compounds capable of forming such carboxylates, said process being characterized in that one operates in the presence of a carboxylic acid salt.
  • an etherification agent chosen from the group consisting of alkyl carboxylates, the linear alkyl radical. or branched having 1 to 6 carbon atoms, the alkenyl carboxylates, the linear or branched alkenyl radical having 3 to 6 carbon atoms and the compounds capable of forming such carboxylates
  • the process according to the invention is more particularly applied to phenol, naphthol-1, naphthol-2, 2-methyl phenol, 3-methyl phenol, 4-methyl phenol, monochlorophenols, dichlorophenols, monoethylphenols, pyrocatechol, resorcinol, hydroquinone, 1,2-dihydroxy naphthalene, 1,3-dihydroxy naphthalene, 1,4-dihydroxy naphthalene, 1,5-dihydroxy naphthalene, 1,6-dihydroxy naphthalene , to 1,7-dihydroxy naphthalene, to 1,8-dihydroxy naphthalene, to 2,3-dihydroxy naphthalene, to 2,6-dihydroxy naphthalene, to 2,7-dihydroxy naphthalene.
  • the concentration of the phenolic compound of formula (I) in the reaction medium is not critical. It varies very widely, in particular as a function of the solubility of this compound in said medium, which is constituted by the etherification agent, the carboxylic acid salt and, where appropriate, by other elements which will be detailed below. and which may consist in particular of non-essential adjuvants, but favorable to the implementation of the process according to the invention and / or in a third solvent.
  • the concentration of the phenolic compound will be expressed relative to the liquid medium, that is to say to the reaction medium from which the phenolic compound itself and the carboxylic acid salt are excluded.
  • esters in situ and in particular a mixture of an alcohol such as those listed above with a carboxylic acid such as those defined above.
  • This variant is the one which is preferred in particular for reasons of convenience, these reagents sometimes being more readily available than the esters themselves.
  • alcohol and carboxylic acid it is not necessary to have stoichiometric amounts of alcohol and carboxylic acid.
  • the etherification reaction is generally faster with these reagents than with the esters.
  • the alcohol / carboxylic acid molar ratio can vary within wide limits, for example between 0.02 and 50, more frequently between 0.1 and 40.
  • the carboxylic acid / phenolic compound molar ratio can also vary very widely. Generally it is between 0.1 and 100. Preferably this ratio is between 0.5 and 50.
  • this term will include both the ester itself and the mixtures in the proportions defined above of the alcohol and the corresponding carboxylic acid.
  • the amount of etherifying agent used is generally chosen such that the ester and / or alcohol molar ratio used in the composition of said etherifying agent on phenolic compound of formula (I) is equal to or greater than 0.5 and preferably equal to or greater than 1.
  • saturated aliphatic monoacids such as acetic acid, propanoic, n-butanoic, 2-methyl propanoic, n-pentanoic, 2-methyl butanoic, 3-methyl butanoic, 3,3-dimethyl butanoic, n-hexanoic, 2-methyl pentanoic, 3-methyl pentanoic, 4-methyl pentanoic; unsaturated aliphatic monoacids like propenoic, 2-butene-oic, 2-methylpropenoic, butene-3-oic, 2-methyl-butene-2-oic cis (angelic acid), 2-methyl-2-butene-oic trans ( tiglic acid), pentene-4 oic, hexene-3 oic, hexene-4 oic; saturated aliphatic diacids such as malonic acid, succinic acid, glutaric acid, adipic
  • the generally preferred etherifying agents are the esters of methanol, ethanol, n-propanol, propene-2 ol-1 and 2-methyl propene-2 ol-1 and a carboxylic acid, or mixtures as defined above of one of these alcohols with a carboxylic acid.
  • the carboxylic acid is frequently chosen from saturated mono- or difunctional aliphatic acids having 2 to 6 carbon atoms, benzoic acid and ortho-, meta- or terephthalic acids.
  • methanol esters and ethanol esters especially their acetates or mixtures consisting of methanol and one of these carboxylic acids or ethanol and one of these carboxylic acids and especially mixtures consisting of one of these two alcohols with acetic acid.
  • the etherification agent can constitute the solvent medium in which the etherification reaction takes place according to the process of the invention. But it is understood that one can also use a third solvent, liquid under the conditions of implementation of the process, insofar as said third solvent is inert with respect to the reactants and stable at the temperatures at which the reaction is carried out .
  • Water can be used as a third solvent. But its presence provides a particular advantage and plays a remarkable role, distinct from the simple role of a third solvent. Indeed, the presence of water leads to an increase in the yield of monoether of the phenolic compound and to a correlative decrease in the parasitic reactions.
  • this can represent from 1% to 95% by volume of the liquid reaction medium.
  • the liquid reaction medium comprises from 20% to 80% by volume of water.
  • the carboxylic acid salt serving as catalyst in the process according to the invention can be any carboxylate, in particular the carboxylates of alkali metals, of ammonium and of alkaline earth metals.
  • carboxylates of alkali metals of ammonium and of alkaline earth metals.
  • the carboxylic acids used to obtain such carboxylates can be mono- or polyfunctional, saturated or unsaturated aliphatic, aromatic, arylaliphatic, cycloaliphatic acids, the rings of which can be substituted by one or more radicals.
  • esters serving as etherification agents can be, for example, those which have been mentioned above when defining the esters serving as etherification agents.
  • the salts of saturated, monofunctional aliphatic carboxylic acids having from 2 to 6 carbon atoms are generally preferred, such as in particular acetic acid, propanoic acid, n-butanoic, n-pentanoic, n-hexanoic acid, 2-methyl propanoic acid, methyl - 2-butanoic acid, methyl 3-butanoic acid, dimethyl-3,3 butanoic, the 2-methyl pentanoic, 3-methyl pentanoic and 4-methyl pentanoic, or difunctional having 3 to 6 carbon atoms, such as in particular malonic acid, succinic acid, glutaric acid and adipic acid, the salts of benzoic acid and those of orthophthalic, isophthalic and terephthalic acids.
  • the alkali metal salts are preferred.
  • the sodium or potassium salts of these acids are used.
  • sodium acetate, sodium propionate and sodium succinate are preferably used.
  • the etherifying agent and the carboxylic acid salt serving as the catalyst so that they originate (or contain) the same carboxylic acid, but this is not essential.
  • the amount of carboxylic acid salt present in the medium can vary within wide limits. If this quantity is expressed relative to the phenolic compound, it is generally not less than 0.05 times the weight of said phenolic compound. The maximum amount is not critical. Usually it does not exceed 50 times the weight of the phenolic compound. It is most often preferred to use weight ratios of carboxylic acid salt / phenolic compound varying from 0.1 to 20.
  • An interesting variant consists in using a dicarboxylic acid of which an acid function is salified, in general with an alkali metal, and the other function of which is either free or esterified with an alcohol such as those previously mentioned, most often the methanol or ethanol.
  • the following embodiment of the process is preferably chosen according to the 'invention.
  • the relative amounts of the various reactants or constituents of the reaction mixture are then chosen from the preferential zones indicated above.
  • the method according to the invention requires for its implementation a heating of the reagents; the temperature at which one operates can vary from 150 ° C. to 350 ° C. It is preferably between 220 ° C and 300 ° C.
  • Pressure is not a critical parameter of the reaction. Usually it is constituted by the autogenous pressure obtained by heating, to the desired temperature, of the reaction mixture in a suitable closed apparatus. It is generally between 10 bars and 100 bars. However, it can reach higher values because it is possible, without departing from the scope of the invention, to create in the apparatus used for the reaction, an initial cold pressure greater than atmospheric pressure, for example by means of an inert gas such as nitrogen.
  • the apparatus used is not specific to the process of the invention. Simply it must have certain characteristics: it must be able to withstand the pressures that are reached during heating, it must be waterproof and obviously not be attacked by the reagents used.
  • the process according to the invention can be implemented in the following manner: the various constituents of the reaction mixture, as defined above, are loaded into the appropriate apparatus. It is heated to the desired temperature, preferably with stirring but without this being truly essential, for a period which can vary from a few minutes to more than 20 hours for example. However, this duration is generally of the order of a few hours, for example from 2 hours to 10 hours depending on the temperature at which one operates.
  • the apparatus is cooled and the final reaction mass is treated in a conventional manner, depending on the reagents used; if the medium contains water, the organic compounds other than the carboxylic acid salt are extracted with an immiscible solvent at the water. If the medium contains little or no water, the carboxylic acid salt can generally be separated by filtration, either directly or after having precipitated it by adding an organic solvent in which it is not soluble. , but which dissolves the compounds formed during the reaction. It is also possible to add water to the medium before proceeding with the extraction of the organic compounds.
  • the products obtained are separated, in particular from the phenolic compound which has not been transformed, by current operations in the field of chemistry, then assayed if necessary, also by methods well known to those skilled in the art.
  • a process for separating the ethers formed during the reaction consists in particular in extracting them using a suitable water-immiscible solvent.
  • Cyclohexane can be used, for example, as an extraction solvent.
  • the operation is carried out at a temperature between 50 ° C. and the boiling point of the final reaction mixture. In general, this non-critical temperature is of the order of 60 ° C.
  • the vast majority of the etherification products formed are thus extracted, while the untransformed phenol remains essentially in the reaction medium with the carboxylic acid salt and the free carboxylic acid.
  • the final reaction mass obtained after extraction can thus be recycled after a possible addition of etherification agent.
  • the monoethers obtained by the process according to the invention can either be used directly or serve as intermediates for the synthesis of more complex compounds.
  • 2-methoxyphenol for example is used in the pharmaceutical industry; it also serves as an intermediary for the preparation of vanillin.
  • the tube is sealed, then heated to 250 ° C with stirring and maintained at this temperature for 5 hours.
  • the tube is sealed, then heated with stirring to 250 ° C and maintained for 5 hours at this temperature.
  • Example 1 The test is carried out under the conditions of Example 1. The treatment of the final reaction mixture and the assay are also the same as in Example 1.
  • the tube is sealed, then heated with stirring to 250 ° C. and kept at this temperature for 4 hours.
  • Example 1 The test is carried out under the conditions of Example 1; the treatment of the final reaction mixture and the dosages are also the same as in Example 1.
  • Example 1 The test is carried out under the conditions of Example 1; the treatment of the final reaction mixture and the dosage are also the same as in Example 1.
  • Example 1 The procedure is as in Example 1 but the test is maintained for 4 hours at 200 ° C. Processing the final reaction mixture and dosing are the same as in Example 1 after addition of water.
  • Example 1 The procedure is as in Example 1, but the test is maintained for 4 i hours at 200 ° C.
  • the treatment of the final mixture and the dosage are the same as in Example 1 after addition of water.
  • 1,2-dimethoxy-benzene is not detected by chromatography.
  • a selectivity (RT) of about 95% the pyrocatechol monoethyl ether (guetol) is obtained.
  • the transformation rate of pyrocatechol is close to 15%.
  • the content of 1,2-diethoxybenzene is less than 2%.
  • the monomethyl ether of hydroquinone is obtained with a yield of approximately 95%, the conversion rate of hydroquinone being 10%.
  • the almost complete absence of 1,4-dimethoxy benzene (less than 2%) is noted.
  • the following reagents are introduced into a pressure-resistant glass tube: The procedure is as in Example 1.
  • the treatment of the final reaction mixture and the assays are carried out by gas / liquid chromatography and by liquid chromatography.
  • the following reagents are introduced into a pressure-resistant glass tube: The procedure is as in Example 1.
  • the treatment of the final reaction mixture and the assays are carried out by gas / liquid chromatography and by liquid chromatography.
  • the following reagents are introduced into a pressure-resistant glass tube: The procedure is as in Example 1.
  • the treatment of the final reaction mixture and the assays are carried out by gas / liquid chromatography and by liquid chromatography.
  • the tube is sealed, then heated to 210 ° C. with stirring and kept at this temperature for 5 h 30 min.
  • test is carried out under the same conditions as test A and the final mixture is dosed as above.
  • test is carried out under the same conditions as test A, but the holding time at 210 ° C. is 5 hours.
  • the treatment consists in the extraction of organic compounds with isopropyl ether.
  • the organic solution obtained is assayed by chromatography.

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Abstract

1. Process for the etherification of a phenol group in a compound of the general formula (I) : HO-Ar-(R)n in which : - Ar represents an aromatic radical consisting of a benzene ring or of several ortho-fused or ortho- and perifused benzene rings, - the substituents R, which are identical or different, represent a hydroxyl group, a linear or branched alkyl radical having from 1 to 6 carbon atoms, a linear or branched alkenyl radical having 2 to 6 carbon atoms, a phenyl radical, a cycloalkyl radical, a phenylalkyl radical in which the aliphatic chain contains 1 to 4 carbon atoms, a cycloalkyl-alkyl radical in which the aliphatic chain contains from 1 to 4 carbon atoms, a halogen atom, a nitro group, an amine group, an aldehyde group or a nitrile group, and - n is a number from 0 to 5, by reaction with an etherifying agent chosen from the group comprising alkyl carboxylates, the linear or branched alkyl radical having 1 to 6 carbon atoms, alkenyl carboxylates, the linear or branched alkenyl radical having 3 to 6 carbon atoms, and compounds capable of forming such carboxylates, characterised in that the reaction is carried out in the presence of a carboxylic acid salt chosen from amongst alkali metal, ammonium or alkaline earth metal carboxylates.

Description

La présente invention concerne un nouveau procédé d'éthérification sélective d'une fonction phénolique de composés pouvant en comporter plusieurs.The present invention relates to a new process for the selective etherification of a phenolic function of compounds which may contain several.

Il est connu d'éthérifier les fonctions phénoliques à l'aide d'un sulfate d'alkyle ou d'un halogénure d'alkyle (HOUBEN-WEYL Methoden der Organischen Chemie, Vol. III, page 54 (1965)).It is known to etherify the phenolic functions using an alkyl sulphate or an alkyl halide (HOUBEN-WEYL Methoden der Organischen Chemie, Vol. III, page 54 (1965)).

Cette méthode peut permettre d'obtenir sélectivement un monoéther lorsque l'on utilise des quantités stoechiométriques de réactifs. Mais les réactifs mis en oeuvre sont chers et, en outre, la réaction donne naissance à des sels minéraux posant des problèmes de corrosion des appareillages et de toxicité des effluents.This method can make it possible to selectively obtain a monoether when stoichiometric quantities of reagents are used. However, the reagents used are expensive and, in addition, the reaction gives rise to mineral salts posing problems of corrosion of the equipment and toxicity of the effluents.

Récemment la demande de brevet japonais n° 79/030.123 a montré que l'on peut éthérifier les fonctions phénoliques de composés aromatiques dihydroxylés, par l'action de phosphates d'alkyle ; mais il n'est pas possible d'empêcher une réaction importante de diéthérification.Recently Japanese patent application No. 79/030.123 has shown that it is possible to etherify the phenolic functions of dihydroxy aromatic compounds, by the action of alkyl phosphates; but it is not possible to prevent a significant dietherification reaction.

La demande de brevet français n° 74-18.172 (publiée sous le numéro 2.231.649) décrit un procédé d'éthérification de composés phénoliques, ayant un ou plusieurs groupements hydroxyle, par un alcool aliphatique saturé ayant 1 à 4 atomes de carbone ou un ester d'un tel alcool et d'un acide aliphatique saturé carboxylique, en présence d'une amine tertiaire aliphatique ou d'un chlorure, d'un sulfate ou d'un carboxylate d'une telle amine. Cependant il s'avère que, lorsque ce procédé est appliqué à un composé phénolique dihydroxylé, on obtient un mélange de mono- et de diéthers.French patent application n ° 74-18.172 (published under number 2.231.649) describes a process for the etherification of phenolic compounds, having one or more hydroxyl groups, with a saturated aliphatic alcohol having 1 to 4 carbon atoms or a ester of such an alcohol and of a saturated aliphatic carboxylic acid, in the presence of an aliphatic tertiary amine or of a chloride, a sulfate or a carboxylate of such an amine. However, it turns out that when this process is applied to a dihydroxylated phenolic compound, a mixture of mono- and diethers is obtained.

Enfin la demande de brevet français n° 77-37263 (publiée sous le n° 2 373 506) décrit un procédé de préparation d'oxydes d'alkyle et d'aryle par réaction, en présence de résines échangeuses de cations fortement acides, d'un composé aromatique hydroxylé avec un alcool aliphatique, ce procédé se caractérisant en ce que l'on opère avec au moins 3 moles de composé aromatique hydroxylé par mole d'alcool aliphatique. La température de mise en oeuvre du procédé est située de préférence entre 110°C et 130°C. Ce procédé permet d'obtenir sélectivement le monoéther à partir d'un polyphénol. Le principal inconvénient d'un tel procédé réside dans la cherté des résines utilisées comme catalyseur et dans leur sensibilité à la chaleur qui risque de provoquer leur dégradation.Finally, French patent application No. 77-37263 (published under No. 2,373,506) describes a process for the preparation of alkyl and aryl oxides by reaction, in the presence of strongly acid cation exchange resins, d an aromatic compound hydroxylated with an aliphatic alcohol, this process being characterized in that one operates with at least 3 moles of aromatic compound hydroxylated per mole of aliphatic alcohol. The process implementation temperature is preferably between 110 ° C and 130 ° C. This process makes it possible to selectively obtain the monoether from a polyphenol. The main disadvantage of such a process lies in the high cost of the resins used as catalyst and in their sensitivity to heat which risks causing their degradation.

Il a maintenant été trouvé un nouveau procédé, constituant la présente invention, qui met en jeu des réactifs peu coûteux et qui conduit à l'éthérification sélective d'une fonction phénolique d'un composé pouvant en comporter plusieurs.A new process has now been found, constituting the present invention, which uses inexpensive reagents and which leads to the selective etherification of a phenolic function of a compound which may contain several.

L'éthérification est dite sélective parce qu'au cours de la mise en oeuvre du procédé selon l'invention, une seule fonction phénolique est éthérifiée, lorsque ledit composé phénolique en comporte plusieurs sur le même cycle aromatique.Etherification is said to be selective because during the implementation of the process according to the invention, a single phenolic function is etherified, when said phenolic compound comprises several of them on the same aromatic cycle.

Plus précisément, l'invention a pour objet un nouveau procédé d'éthérification d'une fonction phénolique d'un composé de formule générale :

Figure imgb0001
dans laquelle :

  • - Ar représente un radical aromatique constitué par un cycle benzénique ou par une structure formée par plusieurs cycles benzéniques orthocondensés ou ortho- et péricondensés,
  • - les substituants R, identiques ou différents, représentent un groupement hydroxyle, un radical-alkyle linéaire ou ramifié ayant de 1 à 6 atomes de carbone, un radical alkényle linéaire ou ramifié ayant 2 à 6 atomes de carbone, un radical phényle éventuellement substitué, un radical cycloalkyle éventuellement substitué, un radical phénylalkyle dans lequel la chaîne aliphatique comporte 1 à 4 atomes de carbone, un radical cycloalkylalkyle dans lequel la chaîne aliphatique comporte de 1 à 4 atomes de carbone, un atome d'halogène, un groupement nitro, un groupement amine, un groupement aldéhyde -CHO, ou un groupement nitrile,
  • - n est un nombre de 0 à 5,

par réaction avec un agent d'éthérification choisi dans le groupe constitué par les carboxylates d'alkyle, le radical alkyle linéaire ou ramifié ayant 1 à 6 atomes de carbone, les carboxylates d'alkényle, le radical alkényle linéaire ou ramifié ayant 3 à 6 atomes de carbone et les composés susceptibles de former de tels carboxylates, caractérisé en ce que l'on opère en présence d'un sel d'acide carboxylique.More specifically, the subject of the invention is a new process for the etherification of a phenolic function of a compound of general formula:
Figure imgb0001
 in which :
  • - Ar represents an aromatic radical constituted by a benzene ring or by a structure formed by several orthocondensed or ortho- and pericondensed benzene cycles,
  • - the substituents R, identical or different, represent a hydroxyl group, a radical - linear or branched alkyl having 1 to 6 carbon atoms, a linear alkenyl chain or branched having 2 to 6 carbon atoms, an optionally substituted phenyl radical, an optionally substituted cycloalkyl radical, a phenylalkyl radical in which the aliphatic chain contains 1 to 4 carbon atoms, a cycloalkylalkyl radical in which the aliphatic chain contains from 1 to 4 carbon atoms, a halogen atom, a nitro group, a amine group, an aldehyde group -CHO, or a nitrile group,
  • - n is a number from 0 to 5,

by reaction with an etherification agent chosen from the group consisting of alkyl carboxylates, the linear or branched alkyl radical having 1 to 6 carbon atoms, the alkenyl carboxylates, the linear or branched alkenyl radical having 3 to 6 carbon atoms and them compounds capable of forming such carboxylates, characterized in that one operates in the presence of a carboxylic acid salt.

L'invention peut également être présentée comme un procédé de préparation de monoéther de phénol par réaction d'un composé de formule générale (I) avec un agent d'éthérification choisi dans le groupe constitué par les carboxylates d'alkyle, le radical alkyle linéaire ou ramifié ayant 1 à 6 atomes de carbone, les carboxylates d'alkényle, le radical alkényle linéaire ou ramifié ayant 3 à 6 atomes de carbone et les composés susceptibles de former de tels carboxylates, ledit procédé se caractérisant en ce que l'on opère en présence d'un sel d'acide carboxylique.The invention can also be presented as a process for the preparation of phenol monoether by reaction of a compound of general formula (I) with an etherification agent chosen from the group consisting of alkyl carboxylates, the linear alkyl radical. or branched having 1 to 6 carbon atoms, the alkenyl carboxylates, the linear or branched alkenyl radical having 3 to 6 carbon atoms and the compounds capable of forming such carboxylates, said process being characterized in that one operates in the presence of a carboxylic acid salt.

De manière préférée, on applique le procédé à des composés phénoliques de formule (I) dans laquelle :

  • - le radical Ar correspond au benzène, au naphtalène, à l'anthracène ou au phénanthrène,
  • - les substituants R, identiques ou différents, représentent un groupement hydroxyle, un radical alkyle linéaire ou ramifié ayant 1 à 4 atomes de carbone tel que méthyle, éthyle, isopropyle, n-propyle, n-butyle, isobutyle ou tertiobutyle, un radical alkényle linéaire ou ramifié ayant 2 à 4 atomes de carbone, tel que vinyle, allyle, propène-1 yle, isopropényle, butène-1 yle, butène-2 yle, butène-3 yle, méthyl-1 propène-1 yle, méthyl-1 propène-2 yle, méthyl-2 propène-1 yle, méthyl-2 propène-2 yle, un radical phényle éventuellement substitué, un radical cyclohexyle éventuellement substitué, un radical phénylalkyle dans lequel la chaîne aliphatique comporte de 1 à 3 atomes de carbone tel que benzyle, phénéthyle, phénylpropyle et phénylisopropyle, un radical cyclohexylalkyle dans lequel la chaîne aliphatique comporte 1 à 3 atomes de carbone, un atome de chlore, un atome de brome ou un groupement nitro,
  • - n est un nombre entier de 0 à 3.
Preferably, the process is applied to phenolic compounds of formula (I) in which:
  • the radical Ar corresponds to benzene, naphthalene, anthracene or phenanthrene,
  • - the substituents R, identical or different, represent a hydroxyl group, a linear or branched alkyl radical having 1 to 4 carbon atoms such as methyl, ethyl, isopropyl, n-propyl, n-butyl, isobutyl or tert-butyl, an alkenyl radical linear or branched having 2 to 4 carbon atoms, such as vinyl, allyl, propene-1 yl, isopropenyl, butene-1 yl, butene-2 yl, butene-3 yl, methyl-1 propene-1 yl, methyl-1 propene-2 yl, 2-methyl propene-1 yl, 2-methyl propene-2 yl, an optionally substituted phenyl radical, an optionally substituted cyclohexyl radical, a phenylalkyl radical in which the aliphatic chain contains from 1 to 3 carbon atoms such that benzyl, phenethyl, phenylpropyl and phenylisopropyl, a cyclohexylalkyl radical in which the aliphatic chain contains 1 to 3 carbon atoms, a chlorine atom, a bromine atom or a nitro group,
  • - n is an integer from 0 to 3.

A titre d'exemples de tels composés phénoliques, on peut citer :

  • - les monophénols comme le phénol, le naphtol-1, le naphtol-2, le phénanthrol-1, le phénanthrol-2, le phénanthrol-3, le phénanthrol-9, l'anthrol-1, l'anthrol-2, l'anthrol-9
  • - les diphénols comme le résorcinol, la pyrocatéchol, l'hydroquinone, le dihydroxy-1,2 naphtalène, le dihydroxy-1,3 naphtalène, le dihydroxy-1,4 naphtalène, le dihydroxy-1,5 naphtalène, le dihydroxy-1,$ naphtalène, le dihydroxy-1,7 naphtalène, le dihydroxy-1,8 naphtalène, le dihydroxy-2,3 naphtalène, le dihydroxy-2,6 naphtalène, le dihydroxy-2,7 naphtalène, le dihydroxy-1,2 anthracène, le dihydroxy-1,5 anthracène, le dihydroxy-1,8 anthracène, le dihydroxy-2,6 anthracène, le dihydroxy-9,10 anthracène, le dihydroxy-3,4 phénanthrène,
  • les triphénols comme le pyrogallol, le trihydroxy-1,2,4 benzène, le trihydroxy-1,3,5 benzène, le trihydroxy-1,2,9 anthracène, le trihydroxy-1,2,10 anthracène, le trihydroxy-1,4,9 anthracène, le trihydroxy-1,5,9 anthracène, le trihydroxy-1,8,9 anthracène, le trihydroxy-2,3,9 anthracène, le trihydroxy-3,4,5 phénanthrène,
  • les mono- ou diphénols portant également 1 ou plusieurs autres substituants R comme : le chloro-2 phénol, le chloro-3 phénol, le chloro-4 phénol, le bromo-2 phénol, le bromo-3 phénol, le bromo-4 phénol, le nitro-2 phénol, le nitro-3 phénol, le nitro-4 phénol, le méthyl-2 phénol, le méthyl-3 phénol, le méthyl-4 phénol, l'éthyl-2 phénol, l'éthyl-3 phénol, l'éthyl-4 phénol, l'isopropyl-2 phénol, l'isopropyl-3 phénol, l'isopropyl-4 phénol, le propyl-2 phénol, le propyl-3 phénol, le propyl-4 phénol, le (propène-1 yle)-4 phénol, l'allyl-2 phénol, l'allyl-4 phénol, le butyl-3 phénol, le butyl-4 phénol, l'isobutyl-4 phénol, le tertiobutyl-2 phénol, le tertiobutyl-3 phénol, le tertiobutyl-4 phénol, le benzyl-2 phénol, le benzyl-4 phénol, le cyclohexyl-2 phénol, le dichloro-2,3 phénol, le dichloro-2,4 phénol, le dichloro-2,5 phénol, le dichloro-2,6 phénol, le dichloro-3,4 phénol, le dichloro-3,5 phénol, le diméthyl-1,2 hydroxy-3 benzène, le diméthyl-1,2 hydroxy-4 benzène, le diméthyl-1,3 hydroxy-5 benzène, le diméthyl-1,3 hydroxy-2 benzène, le diméthyl-1,4 hydroxy-2 benzène, le diméthyl-2,4 hydroxy-1 benzène, le tertiobutyl-1 hydroxy-2 méthyl-4 benzène, le tertiobutyl-2 hydroxy-1 méthyl-4 benzène, le tertiobutyl-2 éthyl-4 hydroxy-1 benzène, le tertiobutyl-4 éthyl-2 hydroxy-1 benzène, le ditertiobutyl-1,3 hydroxy-2 benzène, le ditertiobutyl-2,4 hydroxy-1 benzène, l'hydroxy-2 isopropyl-4 méthyl-1 benzène, l'allyl-2 chloro-4 hydroxy-1 benzène, l'hydroxy-1 triméthyl-2,4,5 benzène, l'hydroxy-2 triméthyl-1,3,5 benzène, l'hydroxy-2 tritertiobutyl-1,3,5 benzène, le ditertiobutyl-1,3 hydroxy-2 méthyl-5 benzène, le ditertiobutyl-1,5 hydroxy-2 méthyl-3 benzène, le ditertiobutyl-1,5 hydroxy-2 méthyl-4 benzène, le tertiobutyl-1 diméthyl-2,5 hydroxy-4 benzène, le tertiobutyl-1 diméthyl-3,5 hydroxy-2 benzène, le tertiobutyl-1 diméthyl-4,5 hydroxy-2 benzène, le tertiobutyl-5 diméthyl-1,3 hydroxy-2 benzène, le chloro-1 diméthyl-2,3 hydroxy-4 benzène, le chloro-1 diméthyl-2,3 hydroxy-5 benzène, le chloro-1 diméthyl-2,4 hydroxy-5 benzène, le chloro-1 diméthyl-2,5 hydroxy-4 benzène, le chloro-1 diméthyl-3,4 hydroxy-2 benzène, le chloro-1 diméthyl-4,5 hydroxy-2 benzène, le chloro-2 diméthyl-1,3 hydroxy-5 benzène, le chloro-2 diméthyl-1,5 hydroxy-3 benzène, le chloro-2 diméthyl-3,4 hydroxy-1 benzène, le chloro-5 diméthyl-1,3 hydroxy-2 benzène, le diméthyl-1,2 hydroxy-3 nitro-5 benzène, le diméthyl-1,2 hydroxy-4 nitro-5 benzène, le diméthyl-1,3 hydroxy-2 nitro-4 benzène, le diméthyl-1,3 hydroxy-2 nitro-5 benzène, le diméthyl-1,4 hydroxy-2 nitro-3 benzène, le diméthyl-1,4 hydroxy-2 nitro-5 benzène, le diméthyl-1,5 hydroxy-2 nitro-3 benzène, le diméthyl-1,5 hydroxy-3 nit o-2 benzène, le diméthyl-2,5 hydroxy-1 nitro-3 benzène, le nitro-8 naphtol-1, le nitro-1 naphtol-2, le nitro-5 naphtol-2, le méthyl-1 naphtol-2, le bromo-1 dihydroxy-2,4 benzène, le bromo-1 dihydroxy-3,5 benzène, le bromo-2 dihydroxy-1,3 benzène, le bromo-2 dihydroxy-1,4 benzène, le bromo-4 dihydroxy-1,2 benzène, le butyl-1 dihydroxy-2,4 benzène, le chloro-1 dihydroxy-2,3 benzène, le chloro-1 dihydroxy-2,4 benzène, le chloro-1 dihydroxy-3,5 benzène, le chloro-2 dihydroxy-1,3 benzène, le chloro-2 dihydroxy-1,4 benzène, le chloro-4 dihydroxy-1,2 benzène, le dihydroxy-2,4 éthyl-1 benzène, le dihydroxy-2,4 isobutyl-1 benzène, le dihydroxy-1,2 isopropyl-4 benzène, le dihydroxy-1,4 isopropyl-2 benzène, le dihydroxy-2,4 isopropyl-1 benzène, le dihydroxy-2,3 isopropyl-1 méthyl-4 benzène, le dihydroxy-1,4 isopropyl-2 méthyl-5 benzène, le dihydroxy-1,2 méthyl-3 benzène, le dihydroxy-1,3 méthyl-2 benzène, le dihydroxy-1,3 nitro-2 benzène, le dihydroxy-1,4 nitro-2 benzène, le dihydroxy-1,2 propyl-4 benzène, le dihydroxy-1,3 propyl-5 benzène, le dihydroxy-2,4 propyl-1 benzène, le dichloro-1,2 dihydroxy-4,5 benzène, le dichloro-1,3 dihydroxy-2,5 benzène, le dichloro-1,4 dihydroxy-2,5 benzène, le dichloro-1,5 dihydroxy-2,3 benzène, le dichloro-1,5 dihydroxy-2,4 benzène, le dichloro-2,3 dihydroxy-1,4 benzène, le dihydroxy-1,2 diméthyl-3,5 benzène, le dihydroxy-1,2 diméthyl-4,5 benzène, le dihydroxy-1,3 diméthyl-2,4 benzène, le dihydroxy-1,3 diméthyl-2,5 benzène, le dihydroxy-1,4 diméthyl-2,3 benzène, le dihydroxy-1,4 diméthyl-2,5 benzène, le dihydroxy-1,5 diméthyl-2,4 benzène, le dihydroxy-1,5 diméthyl-3,4 benzène, le dihydroxy-2,5 diméthyl-1,3 benzène, le dihydroxy-1,3 dinitro-2,4 benzène.
As examples of such phenolic compounds, there may be mentioned:
  • - monophenols such as phenol, naphthol-1, naphthol-2, phenanthrol-1, phenanthrol-2, phenanthrol-3, phenanthrol-9, anthrol-1, anthrol-2, l 'anthrol-9
  • - diphenols such as resorcinol, the pyrocatechol, hydroquinone, 1,2-dihydroxy naphthalene, 1,3-dihydroxy naphthalene, 1,4-dihy d roxy naphthalene, dihydroxy-1,5 naphthalene, dihydroxy-1, $ naphthalene, dihydroxy-1,7 naphthalene, dihydroxy-1,8 naphthalene, dihydroxy-2,3 naphthalene, dihydroxy-2,6 naphthalene, dihydroxy-2,7 naphthalene, dihydroxy-1,2 anthracene, dihydroxy-1,5 anthracene, dihydroxy-1,8 anthracene, dihydroxy-2,6 anthracene, dihydroxy-9,10 anthracene, dihydroxy -3.4 phenanthrene,
  • triphenols such as pyrogallol, trihydroxy-1,2,4 benzene, trihydroxy-1,3,5 benzene, trihydroxy-1,2,9 anthracene, trihydroxy-1,2,10 anthracene, trihydroxy-1 , 4.9 anthracene, trihydroxy-1,5,9 anthracene, trihydroxy-1,8,9 anthracene, trihydroxy-2,3,9 anthracene, trihydroxy-3,4,5 phenanthrene,
  • mono- or diphenols also carrying 1 or more other substituents R such as: 2-chloro-phenol, 3-chloro-phenol, 4-chloro-phenol, 2-bromo-phenol, 3-bromo-phenol, 4-bromo-phenol , 2-nitro phenol, 3-nitro phenol, 4-nitro phenol, 2-methyl phenol, 3-methyl phenol, 4-methyl phenol, 2-ethyl phenol, 3-ethyl phenol , 4-ethyl phenol, 2-isopropyl phenol, 3-isopropyl phenol, 4-isopropyl phenol, 2-propyl phenol, 3-propyl phenol, 4-propyl phenol, (propene -1 yle) -4 phenol, allyl-2 phenol, allyl-4 phenol, butyl-3 phenol, butyl-4 phenol, isobutyl-4 phenol, tertiobutyl-2 phenol, tertiobutyl- 3 phenol, tert-butyl - 4-methylphenol, 2-benzyl phenol, benzyl-4 phenol, 2-cyclohexyl phenol, dichloro - 2,3 phenol, 2,4-dichlorophenol, 2,5-dichloro phenol , 2,6-dichloro-phenol, 3,4-dichloro-phenol, 3,5-dichloro-phenol, 1,2-dimethyl-3-hydroxy-benzene, 1,2-dimethyl-4-hydroxy-benzene, dimethyl- 1.3 hyd roxy-5 benzene, 1,3-dimethyl-2-hydroxy benzene, 1,4 dimethyl-2-hydroxy benzene, 2,4 dimethyl-1-hydroxy benzene, tert-butyl-1-hydroxy - 2-methyl-4 benzene, tert-butyl-2-hydroxy-4-methyl-4-benzene, tert-butyl-2-ethyl-4-hydroxy-1 benzene, tert-butyl-4-ethyl-2-hydroxy-1 benzene, ditertiobutyl-1,3 hydroxy-2 benzene, ditertiobutyl 2,4-hydroxy-1 benzene, hydroxy-2 isopropyl-4-methyl-1 benzene, allyl-4 chloro-4 hydroxy-1 benzene, hydroxy-1 trimethyl-2,4,5 benzene, 2-hydroxy-1,3,5-trimethyl benzene, 2-hydroxy-1,3,5-tritertiobutyl benzene, ditertiobutyl-1,3 2-hydroxy-5-methyl-5 benzene, ditertiobutyl-1,5 hydroxy-2 methyl-3 benzene, ditertiobutyl-1,5 hydroxy-2 methyl-4 benzene, tert-butyl-1 dimethyl-2,5 hydroxy-4 benzene, tert-butyl-1 dimethyl-3,5 hydroxy-2 benzene, tert-1-butyl-4,5-dimethyl-2-hydroxy-benzene, tert-butyl-5-dimethyl-1,3-hydroxy-2-benzene, chloro-1 dimethyl-2,3-hydroxy-4 benzene, chloro-1 dimethyl-2, 3 5-hydroxy-benzene, 1-chloro-2,4-dimethyl-5 hydroxy-benzene, 1-chloro-2,5-dimethyl-4-hydroxy benzene, 1-chloro-3,4-dimethyl-2-hydroxy-benzene, chloro -1 4,5-dimethyl-2-hydroxy-benzene, 2-chloro-1,3-dimethyl-5-hydroxy benzene, 2-chloro-1,5-dimethyl-3-hydroxy-3 benzene, 2-chloro-3,4-dimethyl-hydroxy -1 benzene, 5-chloro-1,3-dimethyl-2-hydroxy-benzene, 1,2-dimethyl-3-hydroxy-5-nitro-benzene, 1,2-dimethyl-4-hydroxy-5-nitro-benzene, 1-dimethyl , 3 hydroxy-2 nitro-4 benzene, dimethyl-1,3 hydroxy-2 nitro-5 benzene, dimethyl-1,4 hydroxy-2 nitro-3 benzene, dimethyl-1,4 hydroxy-2 nitro-5 benzene, 1,5-dimethyl-2-hydroxy-nit ro-3 benzene, dimethyl-1,5 hydroxy-3 nit o-2 benzene, dimethyl-2,5 hydroxy-1 nitro-3 benzene, nitro-8 naphthol-1, nitro-1 naphtol-2, nitro-5 naphthol-2, methyl-1 naphthol-2, bromo-1 dihydroxy-2,4 benzene, bromo-1 dihydroxy-3,5 benzene, bromo-2 dihydroxy-1,3 benzene, 2-bromo-1,4-dihydroxy benzene, 4-bromo-1,2-dihydroxy benzene, 1-butyl-2,4-dihydroxy benzene, 1-chloro-2,3-dihydroxy benzene, 1-chloro-dihydroxy-2 , 4 benzene, chloro-1 dihydroxy-3,5 benzene, chloro-2 dihydroxy-1,3 benzene, chloro-2 dihydroxy-1,4 benzene, chloro-4 dihydroxy-1,2 benzene, dihydroxy -2.4 ethyl-1 benzene, 2,4-dihydroxy isobutyl-1 benzene, 1,2-dihydroxy-4-isopropyl benzene, 1,4-dihydroxy-2-isopropyl benzene, 2,4-dihydroxy isopropyl- 1 benzene, 2,3-dihydroxy-1-isopropyl-4-methyl benzene, 1,4-dihydroxy-2-isopropyl-5-methylene benzene, 1,2-dihydroxy-3-methylene benzene, 1,3-dihydroxy methyl- 2 benzene, 1,3-dihydroxy-2 nitro benzene, 1-dihydroxy , 4 2-nitro-benzene, 1,2-dihydroxy-4-propyl-benzene, 1,3-dihydroxy-5-propyl benzene, 2,4-dihydroxy-1-propyl-benzene, 1,2-dichloro-4-dihydroxy, 5 benzene, dichloro-1,3 dihydroxy-2,5 benzene, dichloro-1,4 dihydroxy-2,5 benzene, dichloro-1,5 dihydroxy-2,3 benzene, dichloro-1,5 dihydroxy- 2,4 benzene, 2,3-dichloro 1,4-dihydroxy benzene, 1,2-dihydroxy-3,5-dimethyl benzene, 1,2-dihydroxy-4,5-dimethyl benzene, 1,3-dihydroxy-2,4-dimethyl benzene, 1-dihydroxy , 3 dimethyl-2,5 benzene, 1,4-dihydroxy-2,3-dimethyl benzene, dihydroxy-1,4-dimethyl - 2,5 benzene, 1,5-dihydroxy-2,4-dimethyl benzene, dihydroxy -1.5-3,4-dimethyl benzene, 2,5-dihydroxy-1,3-dimethyl benzene, 1,3-dihydroxy-2,4-dinitro-benzene.

Le procédé selon l'invention est plus particulièrement appliqué au phénol, au naphtol-l, au naphtol-2, au méthyl-2 phénol, au méthyl-3 phénol, au méthyl-4 phénol, aux monochlorophénols, aux dichlorophénols, aux monoéthylphénols, au pyrocatéchol, au résorcinol, à l'hydroquinone, au dihydroxy-1,2 naphtalène, au dihydroxy-1,3 naphtalène, au dihydroxy-1,4 naphtalène, au dihydroxy-1,5 naphtalène, au dihydroxy-1,6 naphtalène, au dihydroxy-1,7 naphtalène, au dihydroxy-1,8 naphtalène, au dihydroxy-2,3 naphtalène, au dihydroxy-2,6 naphtalène, au dihydroxy-2,7 naphtalène.The process according to the invention is more particularly applied to phenol, naphthol-1, naphthol-2, 2-methyl phenol, 3-methyl phenol, 4-methyl phenol, monochlorophenols, dichlorophenols, monoethylphenols, pyrocatechol, resorcinol, hydroquinone, 1,2-dihydroxy naphthalene, 1,3-dihydroxy naphthalene, 1,4-dihydroxy naphthalene, 1,5-dihydroxy naphthalene, 1,6-dihydroxy naphthalene , to 1,7-dihydroxy naphthalene, to 1,8-dihydroxy naphthalene, to 2,3-dihydroxy naphthalene, to 2,6-dihydroxy naphthalene, to 2,7-dihydroxy naphthalene.

La concentration du composé phénolique de formule (I) dans le milieu réactionnel n'est pas critique. Elle varie très largement, notamment en fonction de la solubilité de ce composé dans ledit milieu, qui est constitué par l'agent d'éthérification, le sel d'acide carboxylique et le cas échéant par'd'autres éléments qui seront détaillés plus loin et qui peuvent consister en particulier en des adjuvants non indispensables, mais favorables à la mise en oeuvre du procédé selon l'invention et/ou en un tiers solvant.The concentration of the phenolic compound of formula (I) in the reaction medium is not critical. It varies very widely, in particular as a function of the solubility of this compound in said medium, which is constituted by the etherification agent, the carboxylic acid salt and, where appropriate, by other elements which will be detailed below. and which may consist in particular of non-essential adjuvants, but favorable to the implementation of the process according to the invention and / or in a third solvent.

Pour des raisons de commodité, la concentration du composé phénolique sera exprimée par rapport au milieu liquide, c'est à dire au milieu réactionnel dont on exclut le composé phénolique lui-même et le sel d'acide carboxylique.For reasons of convenience, the concentration of the phenolic compound will be expressed relative to the liquid medium, that is to say to the reaction medium from which the phenolic compound itself and the carboxylic acid salt are excluded.

C'est ainsi que généralement on opére avec de 1 % à 100 % en poids de composé phénolique par rapport au volume du milieu liquide. Le plus fréquemment cette concentration est comprise entre 2 % et 80 % en poids par volumeThus, generally, one operates with from 1% to 100% by weight of phenolic compound relative to the volume of the liquid medium. Most often this concentration is between 2% and 80% by weight per volume

Parmi les agents d'éthérification que l'on peut mettre en oeuvre dans le procédé selon l'invention, on peut citer notamment les esters :

  • - des acides carboxyliques aliphatiques saturés ou insaturés monofonctionnels comportant notamment 2 à 18 atomes de carbone ou polyfonctionnels comportant notamment 3 à 18 atomes de carbone,
  • - des acides aromatiques mono- ou polyfonctionnels,
  • - des acides arylaliphatiques mono- ou polyfonctionnels,
  • - ou des acides cycloaliphatiques mono- ou polyfonctionnels avec des alcools tels que le méthanol, l'éthanol, le n-propanol, l'isopropanol, le butanol-l, le butanol-2, le tertiobutanol, le propène-2 ol-1, le méthyl-2 propène-2 ol-l, le butène-2 ol-1, le butène-3 ol-1, le butène-3 ol-2.
Among the etherification agents which can be used in the process according to the invention, mention may in particular be made of esters:
  • - monofunctional saturated or unsaturated aliphatic carboxylic acids comprising in particular 2 to 18 carbon atoms or polyfunctional comprising in particular 3 to 18 carbon atoms,
  • - mono- or polyfunctional aromatic acids,
  • - mono- or polyfunctional arylaliphatic acids,
  • - or mono- or polyfunctional cycloaliphatic acids with alcohols such as methanol, ethanol, n-propanol, isopropanol, butanol-1, butanol-2, tertiobutanol, propene-2 ol-1 , 2-methyl-propene-2 ol-1, butene-2 ol-1, butene-3 ol-1, butene-3 ol-2.

On peut également mettre en oeuvre des composés susceptibles de former de tels esters in situ et notamment un mélange d'un alcool tel que ceux énumérés ci-avant avec un acide carboxylique tel que ceux définis précédemment. Cette variante est celle qui est préférée notamment pour des raisons de commodité, ces réactifs étant parfois plus facilement disponibles que les esters eux-mêmes. En outre, il n'est pas nécessaire d'avoir des quantités stoechiométriques d'alcool et d'acide carboxylique. Enfin la réaction d'éthérification est en général plus rapide avec ces réactifs qu'avec les esters. Le rapport molaire alcool/acide carboxylique peut varier dans de larges limites, par exemple entre 0,02 et 50, plus fréquemment entre 0,1 et 40. Le rapport molaire acide carboxylique/composé phénolique peut également varier très largement. Généralement il se situe entre 0,1 et 100. De préférence ce rapport est compris entre 0,5 et 50.It is also possible to use compounds capable of forming such esters in situ and in particular a mixture of an alcohol such as those listed above with a carboxylic acid such as those defined above. This variant is the one which is preferred in particular for reasons of convenience, these reagents sometimes being more readily available than the esters themselves. Furthermore, it is not necessary to have stoichiometric amounts of alcohol and carboxylic acid. Finally, the etherification reaction is generally faster with these reagents than with the esters. The alcohol / carboxylic acid molar ratio can vary within wide limits, for example between 0.02 and 50, more frequently between 0.1 and 40. The carboxylic acid / phenolic compound molar ratio can also vary very widely. Generally it is between 0.1 and 100. Preferably this ratio is between 0.5 and 50.

Par la suite lorsqu'il sera question d'agent d'éthérification, ce terme englobera aussi bien l'ester lui-même que les mélanges dans les proportions définies précédemment de l'alcool et de l'acide carboxylique correspondants.Subsequently when it comes to etherifying agent, this term will include both the ester itself and the mixtures in the proportions defined above of the alcohol and the corresponding carboxylic acid.

La quantité d'agent d'éthérification utilisée est généralement choisie de telle façon que le rapport molaire ester et/ou alcool entrant dans la composition dudit agent éthérifiant sur composé phénolique de formule (I) est égal ou supérieur à 0,5 et de préférence égal ou supérieur à 1.The amount of etherifying agent used is generally chosen such that the ester and / or alcohol molar ratio used in the composition of said etherifying agent on phenolic compound of formula (I) is equal to or greater than 0.5 and preferably equal to or greater than 1.

On peut citer à titre d'illustration des acides carboxyliques précédents des monoacides aliphatiques saturés comme l'acide acétique, le propanoïque, le n-butanoïque, le méthyl-2 propanoïque, le n-pentanoïque, le méthyl-2 butanoïque, le méthyl-3 butanoïque, le diméthyl-3,3 butanoïque, le n-hexanoïque, le méthyl-2 pentanoïque, le méthyl-3 pentanoïque, le méthyl-4 pentanoïque ; des monoacides aliphatiques insaturés comme le propènoïque, le butène-2 oïque, le méthyl-2 propènoïque, le butène-3 oïque, le méthyl-2 butène-2 oïque cis (acide angélique), le méthyl-2 butène-2 oïque trans (acide tiglique), le pentène-4 oïque, l'hexène-3 oïque, l'hexène-4 oïque ; des diacides aliphatiques saturés comme l'acide malonique, l'acide succinique, l'acide glutarique, l'acide adipique ; des diacides éthyléniques comme l'acide maléïque et l'acide fumarique ; des mono- ou des diacides aromatiques comme l'acide benzoïque, l'acide orthophtalique, l'acide isophtalique, l'acide téréphtalique, les acides mononitrobenzoïques, les acides monochlorobenzoïques des acides arylaliphatiques comme l'acide phénylacétique, le phényl-2 propanoïque, le phényl-4 propanoïque ; des acides cycloaliphatiques comme l'acide cyclohexanedicarboxylique-1,3, l'acide cyclohexanedicarboxylique-1,4.Mention may be made, by way of illustration of the preceding carboxylic acids, of saturated aliphatic monoacids such as acetic acid, propanoic, n-butanoic, 2-methyl propanoic, n-pentanoic, 2-methyl butanoic, 3-methyl butanoic, 3,3-dimethyl butanoic, n-hexanoic, 2-methyl pentanoic, 3-methyl pentanoic, 4-methyl pentanoic; unsaturated aliphatic monoacids like propenoic, 2-butene-oic, 2-methylpropenoic, butene-3-oic, 2-methyl-butene-2-oic cis (angelic acid), 2-methyl-2-butene-oic trans ( tiglic acid), pentene-4 oic, hexene-3 oic, hexene-4 oic; saturated aliphatic diacids such as malonic acid, succinic acid, glutaric acid, adipic acid; ethylenic diacids such as maleic acid and fumaric acid; mono- or aromatic diacids such as benzoic acid, orthophthalic acid, isophthalic acid, terephthalic acid, mononitrobenzoic acids, monochlorobenzoic acids of arylaliphatic acids such as phenylacetic acid, 2-phenylpropanoic acid, 4-phenylpropanoic; cycloaliphatic acids such as cyclohexanedicarboxylic acid-1,3, cyclohexanedicarboxylic acid-1,4.

On peut également utiliser des mélanges comprenant un ester d'acide carboxylique et l'alcool libre correspondant ou un ester d'acide carboxylique avec l'alcool libre et l'acide carboxylique libre correspondant à cet ester. Dans le présent texte lorsque l'on parle d'agent d'éthérification, il est entendu qu'il peut s'agir d'un tel mélange, sans qu'il soit nécessaire de le préciser chaque fois.It is also possible to use mixtures comprising a carboxylic acid ester and the corresponding free alcohol or a carboxylic acid ester with the free alcohol and the free carboxylic acid corresponding to this ester. In the present text when speaking of an etherifying agent, it is understood that it may be such a mixture, without it being necessary to specify it each time.

Les agents d'éthérification que l'on préfère utiliser généralement sont les esters du méthanol, de l'éthanol, du n-propanol, du propène-2 ol-l et du méthyl-2 propène-2 ol-1 et d'un acide carboxylique, ou les mélanges tels que définis précédemment de l'un de ces alcools avec un acide carboxylique. 0n choisit fréquemment l'acide carboxylique parmi les acides aliphatiques saturés mono- ou difonctionnels ayant 2 à 6 atomes de carbone, l'acide benzoïque et les acides ortho-, méta- ou téréphtaliques. Parmi ces agents d'éthérification, on préfère le plus souvent utiliser les acétates, les propionates et les succinates ou les mélanges constitués par l'acide acétique ou l'acide propionique ou l'acide succinique avec l'un des alcools cités ci-avant.The generally preferred etherifying agents are the esters of methanol, ethanol, n-propanol, propene-2 ol-1 and 2-methyl propene-2 ol-1 and a carboxylic acid, or mixtures as defined above of one of these alcohols with a carboxylic acid. The carboxylic acid is frequently chosen from saturated mono- or difunctional aliphatic acids having 2 to 6 carbon atoms, benzoic acid and ortho-, meta- or terephthalic acids. Among these etherification agents, it is most often preferred to use acetates, propionates and succinates or mixtures consisting of acetic acid or propionic acid or succinic acid with one of the alcohols mentioned above. .

Enfin parmi ces agents d'éthérification préférés, on préfère plus particulièrement employer les esters du méthanol et les esters de l'éthanol, tout spécialement leurs acétates ou les mélanges constitués par le méthanol et l'un de ces acides carboxyliques ou l'éthanol et l'un de ces acides carboxyliques et tout spécialement les mélanges constitués par l'un de ces deux alcools avec l'acide acétique.Finally, among these preferred etherification agents, more preferred particularly use methanol esters and ethanol esters, especially their acetates or mixtures consisting of methanol and one of these carboxylic acids or ethanol and one of these carboxylic acids and especially mixtures consisting of one of these two alcohols with acetic acid.

L'agent d'éthérification peut constituer le milieu solvant dans lequel s'opère la réaction d'éthérification selon le procédé de l'invention. Mais il est bien entendu que l'on peut également utiliser un tiers solvant, liquide dans les conditions de mise en oeuvre du procédé, dans la mesure où ledit tiers solvant est inerte vis à vis des réactifs et stable aux températures auxquelles est effectuée la réaction.The etherification agent can constitute the solvent medium in which the etherification reaction takes place according to the process of the invention. But it is understood that one can also use a third solvent, liquid under the conditions of implementation of the process, insofar as said third solvent is inert with respect to the reactants and stable at the temperatures at which the reaction is carried out .

L'eau peut servir de tiers solvant. Mais sa présence procure un avantage particulier et joue un rôle remarquable, distinct du simple rôle de tiers solvant. En effet la présence d'eau conduit à une augmentation du rendement en monoéther du composé phénolique et à une diminution corrélative des réactions parasites.Water can be used as a third solvent. But its presence provides a particular advantage and plays a remarkable role, distinct from the simple role of a third solvent. Indeed, the presence of water leads to an increase in the yield of monoether of the phenolic compound and to a correlative decrease in the parasitic reactions.

Lorsque l'on opère en présence d'eau, celle-ci peut représenter de 1 % à 95 % en volume du milieu réactionnel liquide. De préférence le milieu réactionnel liquide comprend de 20 % à 80 % en volume d'eau.When operating in the presence of water, this can represent from 1% to 95% by volume of the liquid reaction medium. Preferably the liquid reaction medium comprises from 20% to 80% by volume of water.

Le sel d'acide carboxylique servant de catalyseur dans le procédé selon l'invention peut être tout carboxylate, notamment les carboxylates des métaux alcalins, d'ammonium et des métaux alcalino-terreux. A titre d'exemples, on peut citer notamment les carboxylates de sodium, de potassium, de lithium et d'ammonium ; on peut- également citer les carboxylates de calcium, de magnésium et de baryum.The carboxylic acid salt serving as catalyst in the process according to the invention can be any carboxylate, in particular the carboxylates of alkali metals, of ammonium and of alkaline earth metals. By way of examples, mention may in particular be made of sodium, potassium, lithium and ammonium carboxylates; mention may also be made of calcium, magnesium and barium carboxylates.

Les acides carboxyliques servant à obtenir de tels carboxylates peuvent être les acides mono- ou polyfonctionnels, aliphatiques saturés ou insaturés, aromatiques, arylaliphatiques, cycloaliphatiques dont les cycles peuvent être substitués par un ou plusieurs radicaux.The carboxylic acids used to obtain such carboxylates can be mono- or polyfunctional, saturated or unsaturated aliphatic, aromatic, arylaliphatic, cycloaliphatic acids, the rings of which can be substituted by one or more radicals.

Ces acides peuvent être par exemple ceux qui ont été cités précédemment lors de la définition des esters servant d'agents d'éthérification.These acids can be, for example, those which have been mentioned above when defining the esters serving as etherification agents.

Parmi tous les carboxylates que l'on peut utiliser on préfère généralement les sels des acides carboxyliques aliphatiques saturés, monofonctionnels ayant de 2 à 6 atomes de carbone, tels que notamment l'acide acétique, le propanoïque, le n-butanoïque, le n-pentanoïque, le n-hexanoïque, le méthyl-2 propanoïque, le méthyl-2 butanoïque, le méthyl-3 butanoïque, le diméthyl-3,3 butanoïque, le méthyl-2 pentanoïque, le méthyl-3 pentanoïque et le méthyl-4 pentanoïque, ou difonctionnels ayant 3 à 6 atomes de carbone, tels que notamment l'acide malonique, l'acide succinique, l'acide glutarique et l'acide adipique, les sels de l'acide benzoïque et ceux des acides orthophtalique, isophtalique et téréphtalique. Parmi les sels de ces acides on préfère les sels de métaux alcalins.Among all the carboxylates which can be used, the salts of saturated, monofunctional aliphatic carboxylic acids having from 2 to 6 carbon atoms are generally preferred, such as in particular acetic acid, propanoic acid, n-butanoic, n-pentanoic, n-hexanoic acid, 2-methyl propanoic acid, methyl - 2-butanoic acid, methyl 3-butanoic acid, dimethyl-3,3 butanoic, the 2-methyl pentanoic, 3-methyl pentanoic and 4-methyl pentanoic, or difunctional having 3 to 6 carbon atoms, such as in particular malonic acid, succinic acid, glutaric acid and adipic acid, the salts of benzoic acid and those of orthophthalic, isophthalic and terephthalic acids. Among the salts of these acids, the alkali metal salts are preferred.

De manière encore préférée, on emploie les sels de sodium ou de potassium de ces acides. Parmi ces derniers sels, on utilise préférentiellement l'acétate de sodium, le propionate de sodium et le succinate de sodium.More preferably, the sodium or potassium salts of these acids are used. Among these latter salts, sodium acetate, sodium propionate and sodium succinate are preferably used.

Il est commode de choisir l'agent d'éthérification et le sel d'acide carboxylique servant de catalyseur de telle façon qu'ils proviennent (ou contiennent) du même acide carboxylique, mais cela n'est pas indispensable.It is convenient to choose the etherifying agent and the carboxylic acid salt serving as the catalyst so that they originate (or contain) the same carboxylic acid, but this is not essential.

La quantité de sel d'acide carboxylique présent dans le milieu peut varier dans de larges limites. Si on exprime cette quantité par rapport au composé phénolique, elle n'est généralement pas inférieure à 0,05 fois le poids dudit composé phénolique. La quantité maximale n'est pas critique. Habituellement elle ne dépasse pas 50 fois le poids du composé phénolique. On préfère le plus souvent utiliser des rapports pondéraux sel d'acide carboxylique/composé phénolique variant de 0,1 à 20.The amount of carboxylic acid salt present in the medium can vary within wide limits. If this quantity is expressed relative to the phenolic compound, it is generally not less than 0.05 times the weight of said phenolic compound. The maximum amount is not critical. Usually it does not exceed 50 times the weight of the phenolic compound. It is most often preferred to use weight ratios of carboxylic acid salt / phenolic compound varying from 0.1 to 20.

Une variante intéressante consiste à mettre en oeuvre un diacide carboxylique dont une fonction acide est salifiée, en général par un métal alcalin, et dont l'autre fonction est soit libre, soit estérifiée par un alcool tel que ceux précédemment cités, le plus souvent le méthanol ou l'éthanol.An interesting variant consists in using a dicarboxylic acid of which an acid function is salified, in general with an alkali metal, and the other function of which is either free or esterified with an alcohol such as those previously mentioned, most often the methanol or ethanol.

Sur un plan pratique, afin d'obtenir un très bon rendement en monoéther par rapport au composé phénolique transformé, tout en ayant une mise en oeuvre et un traitement final du mélange réactionnel relativement faciles, on choisit de préférence la réalisation suivante du procédé selon l'invention. On opère généralement dans un milieu constitué par le. mélange alcool + acide carboxylique qui joue le double rôle de réactif et de solvant ; on ajoute également de l'eau, à raison le plus souvent d'un volume égal à celui de l'alcool et un carboxylate de métal alcalin, notamment de sodium, dérivant de l'acide carboxylique libre utilisé.On a practical level, in order to obtain a very good yield of monoether with respect to the transformed phenolic compound, while having a relatively easy implementation and final treatment of the reaction mixture, the following embodiment of the process is preferably chosen according to the 'invention. We generally operate in a medium consisting of. alcohol + carboxylic acid mixture which plays the dual role of reagent and solvent; water is also added, most often at a volume equal to that of the alcohol and an alkali metal carboxylate, in particular of sodium, derived from the free carboxylic acid used.

Les quantités relatives des divers réactifs ou constituants du mélange réactionnel sont alors choisies dans les zones préférentielles indiquées précédemment.The relative amounts of the various reactants or constituents of the reaction mixture are then chosen from the preferential zones indicated above.

Le procédé selon l'invention nécessite pour sa mise en oeuvre un chauffage des réactifs ; la température à laquelle on opère peut varier de 150°C à 350°C. Elle se situe de préférence entre 220°C et 300°C.The method according to the invention requires for its implementation a heating of the reagents; the temperature at which one operates can vary from 150 ° C. to 350 ° C. It is preferably between 220 ° C and 300 ° C.

La pression n'est pas un paramètre critique de la réaction. Habituellement elle est constituée par la pression autogène obtenue par chauffage, à la température désirée, du mélange réactionnel dans un appareillage adéquat fermé. Elle se situe généralement entre 10 bars et 100 bars. Mais elle peut atteindre des valeurs plus élevées car il est possible, sans sortir du cadre de l'invention, de créer dans l'appareil utilisé pour la réaction, une pression initiale à froid supérieure à la pression atmosphérique, par exemple au moyen d'un gaz inerte tel que l'azote.Pressure is not a critical parameter of the reaction. Usually it is constituted by the autogenous pressure obtained by heating, to the desired temperature, of the reaction mixture in a suitable closed apparatus. It is generally between 10 bars and 100 bars. However, it can reach higher values because it is possible, without departing from the scope of the invention, to create in the apparatus used for the reaction, an initial cold pressure greater than atmospheric pressure, for example by means of an inert gas such as nitrogen.

L'appareillage utilisé n'est pas spécifique au procédé de l'invention. Simplement il doit présenter certaines caractéristiques : il doit pouvoir résister aux pressions que l'on atteint lors du chauffage, il doit être étanche et évidemment ne pas être attaqué par les réactifs utilisés.The apparatus used is not specific to the process of the invention. Simply it must have certain characteristics: it must be able to withstand the pressures that are reached during heating, it must be waterproof and obviously not be attacked by the reagents used.

Pratiquement le procédé selon l'invention peut être mis en oeuvre de la manière suivante : on charge les différents constituants du mélange réactionnel, tels que définis précédemment, dans l'appareillage adéquat. On chauffe à la température désirée, de préférence sous agitation mais sans que celà soit véritablement indispensable, pendant une durée pouvant varier de quelques minutes à plus de 20 heures par exemple. Cependant cette durée est généralement de l'ordre de quelques heures, par exemple de 2 heures à 10 heures selon la température à laquelle on opère.Practically the process according to the invention can be implemented in the following manner: the various constituents of the reaction mixture, as defined above, are loaded into the appropriate apparatus. It is heated to the desired temperature, preferably with stirring but without this being truly essential, for a period which can vary from a few minutes to more than 20 hours for example. However, this duration is generally of the order of a few hours, for example from 2 hours to 10 hours depending on the temperature at which one operates.

En fin de réaction, l'appareil est refroidi et la masse réactionnelle finale est traitée de manière classique, selon les réactifs utilisés ; si le milieu contient de l'eau, les composés organiques autres que le sel d'acide carboxylique sont extraits par un solvant non miscible à l'eau. Si le milieu ne contient pas ou très peu d'eau, on peut généralement séparer le sel d'acide carboxylique par filtration, soit directement, soit après l'avoir précipité par addition d'un solvant organique dans lequel il n'est pas soluble, mais qui dissout les composés formés lors de la réaction. On peut aussi rajouter de l'eau au milieu avant de procéder à l'extraction des composés organiques.At the end of the reaction, the apparatus is cooled and the final reaction mass is treated in a conventional manner, depending on the reagents used; if the medium contains water, the organic compounds other than the carboxylic acid salt are extracted with an immiscible solvent at the water. If the medium contains little or no water, the carboxylic acid salt can generally be separated by filtration, either directly or after having precipitated it by adding an organic solvent in which it is not soluble. , but which dissolves the compounds formed during the reaction. It is also possible to add water to the medium before proceeding with the extraction of the organic compounds.

Les produits obtenus sont séparés, notamment du composé phénolique n'ayant pas été transformé, par des opérations courantes dans le domaine de la chimie, puis dosés si nécessaire, également par des méthodes bien connues de l'homme du métier.The products obtained are separated, in particular from the phenolic compound which has not been transformed, by current operations in the field of chemistry, then assayed if necessary, also by methods well known to those skilled in the art.

Un procédé de séparation des éthers formés au cours de la réaction consiste notamment à les extraire à l'aide d'un solvant non miscible à l'eau approprié. On peut utiliser par exemple le cyclohexane comme solvant d'extraction. De préférence on opère à une température comprise entre 50°C et le point d'ébullition du mélange réactionnel final. En général cette température, non critique, est de l'ordre de 60°C. On extrait ainsi la grande majorité des produits d'éthérification formés, tandis que le phénol non transformé reste pour l'essentiel dans le milieu réactionnel avec le sel d'acide carboxylique et l'acide carboxylique libre. La masse réactionnelle finale obtenue après l'extraction peut ainsi être recyclée après un éventuel rajout d'agent d'éthérification.A process for separating the ethers formed during the reaction consists in particular in extracting them using a suitable water-immiscible solvent. Cyclohexane can be used, for example, as an extraction solvent. Preferably, the operation is carried out at a temperature between 50 ° C. and the boiling point of the final reaction mixture. In general, this non-critical temperature is of the order of 60 ° C. The vast majority of the etherification products formed are thus extracted, while the untransformed phenol remains essentially in the reaction medium with the carboxylic acid salt and the free carboxylic acid. The final reaction mass obtained after extraction can thus be recycled after a possible addition of etherification agent.

Les monoéthers obtenus par le procédé selon l'invention peuvent soit être utilisés directement, soit servir d'intermédiaires pour la synthèse de composés plus complexes.The monoethers obtained by the process according to the invention can either be used directly or serve as intermediates for the synthesis of more complex compounds.

Le méthoxy-2 phénol (ou gaïacol) par exemple est utilisé dans l'industrie pharmaceutique ; il sert également d'intermédiaire pour la préparation de la vanilline.2-methoxyphenol (or guaiacol) for example is used in the pharmaceutical industry; it also serves as an intermediary for the preparation of vanillin.

Dans les exemples qui vont suivre les dosages, sauf mention contraire, sont effectués par chromatographie gaz/liquide.In the examples which follow the dosages, unless otherwise stated, are carried out by gas / liquid chromatography.

EXEMPLE 1EXAMPLE 1

Dans un tube de verre résistant à la pression, on introduit les réactifs suivants :

Figure imgb0002
Figure imgb0003
 The following reagents are introduced into a pressure-resistant glass tube:
Figure imgb0002
Figure imgb0003

Le tube est scellé, puis on chauffe à 250°C sous agitation et on maintient à cette température pendant 5 heures.The tube is sealed, then heated to 250 ° C with stirring and maintained at this temperature for 5 hours.

En fin d'essai, on refroidit et on extrait du mélange aqueux le pyrocatéchol non transformé et le gaïacol formé, à l'aide d'éther isopropylique. On dose les produits par chromatographie gaz/liquide. 0n trouve :

  • - Pyrocatéchol non transformé : 0,344 g, soit un taux de transformation (TT) du pyrocatéchol de 32,5 %.
  • - Gaïacol formé : 0,190 g, soit un rendement par rapport au pyrocatéchol transformé (RT) de 100 %.
At the end of the test, the unprocessed pyrocatechol and the guaiacol formed are cooled from the aqueous mixture and extracted with isopropyl ether. The products are assayed by gas / liquid chromatography. We find:
  • - Unprocessed pyrocatechol: 0.344 g, i.e. a transformation rate (TT) of pyrocatechol of 32.5%.
  • - Guaiacol formed: 0.190 g, ie a yield compared to the transformed pyrocatechol (RT) of 100%.

EXEMPLE 2EXAMPLE 2

Dans un tube de verre résistant à la pression, on introduit les réactifs suivants :

Figure imgb0004
The following reagents are introduced into a pressure-resistant glass tube:
Figure imgb0004

Le tube est scellé, puis chauffé sous agitation à 250°C et maintenu 5 heures à cette température.The tube is sealed, then heated with stirring to 250 ° C and maintained for 5 hours at this temperature.

Le mélange réactionnel final est traité et dosé comme dans l'exemple 1 :

Figure imgb0005
The final reaction mixture is treated and assayed as in Example 1:
Figure imgb0005

EXEMPLE 3EXAMPLE 3

Dans un tube de verre résistant à la pression, on introduit les réactifs suivants :

Figure imgb0006
Figure imgb0007
 The following reagents are introduced into a pressure-resistant glass tube:
Figure imgb0006
Figure imgb0007

On effectue l'essai dans les conditions de l'exemple 1. Le traitement du mélange réactionnel final et le dosage sont également les mêmes que dans l'exemple 1.The test is carried out under the conditions of Example 1. The treatment of the final reaction mixture and the assay are also the same as in Example 1.

On trouve les résultats suivants :

Figure imgb0008
The following results are found:
Figure imgb0008

On décèle moins de 5 % (RT) de diméthoxy-1,2 benzène par chromatographie.Less than 5% (RT) of 1,2-dimethoxy-benzene is detected by chromatography.

EXEMPLE 4EXAMPLE 4

Dans un tube de verre résistant à la pression, on introduit les réactifs suivants :

Figure imgb0009
The following reagents are introduced into a pressure-resistant glass tube:
Figure imgb0009

On trouve les résultats suivants :

Figure imgb0010
The following results are found:
Figure imgb0010

On décèle moins de 5 % (RT) de diméthoxy-1,2 benzène par chromatographie.Less than 5% (RT) of 1,2-dimethoxy-benzene is detected by chromatography.

EXEMPLE 5EXAMPLE 5

On effectue l'essai comme pour les exemples 1 et 2 mais avec les réactifs suivants :

Figure imgb0011
The test is carried out as for Examples 1 and 2 but with the following reagents:
Figure imgb0011

On opère dans les mêmes conditions que dans les exemples 1 et 2 mais en maintenant 4 heures à 250° et le mélange final est dosé comme précédemment après addition d'eau et traitement identique à celui de l'exemple 1.

Figure imgb0012
On ne décèle pas de diméthoxy-1,2 benzène par chromatographie.The operation is carried out under the same conditions as in Examples 1 and 2 but maintaining for 4 hours at 250 ° and the final mixture is dosed as before after addition of water and treatment identical to that of Example 1.
Figure imgb0012
 1,2-dimethoxy-benzene is not detected by chromatography.

EXEMPLE 6EXAMPLE 6

Dans un tube de verre résistant à la pression, on introduit les réactifs suivants :

Figure imgb0013
The following reagents are introduced into a pressure-resistant glass tube:
Figure imgb0013

Le tube est scellé, puis chauffé sous agitation à 250°C et maintenu 4 heures à cette température.The tube is sealed, then heated with stirring to 250 ° C. and kept at this temperature for 4 hours.

Le mélange réactionnel final est traité et dosé comme dans l'exemple 1 :

Figure imgb0014
The final reaction mixture is treated and assayed as in Example 1:
Figure imgb0014

EXEMPLE 7EXAMPLE 7

Dans un tube de verre résistant à la pression, on introduit les réactifs suivants :

Figure imgb0015
The following reagents are introduced into a pressure-resistant glass tube:
Figure imgb0015

On effectue l'essai dans les conditions de l'exemple 1 ; le traitement du mélange réactionnel final et les dosages sont également les mêmes que dans l'exemple 1.The test is carried out under the conditions of Example 1; the treatment of the final reaction mixture and the dosages are also the same as in Example 1.

0n trouve les résultats suivants :

Figure imgb0016
The following results are found:
Figure imgb0016

On décèle environ 5 % (RT) de diméthoxy-1,2 benzène par chromatographie.About 5% (RT) of 1,2-dimethoxy-benzene is detected by chromatography.

EXEMPLE 8EXAMPLE 8

Dans un tube de verre résistant à la pression, on introduit les réactifs suivants :

Figure imgb0017
The following reagents are introduced into a pressure-resistant glass tube:
Figure imgb0017

On effectue l'essai dans les conditions de l'exemple 1 ; le traitement du mélange réactionnel final et le dosage sont également les mêmes que dans l'exemple 1.The test is carried out under the conditions of Example 1; the treatment of the final reaction mixture and the dosage are also the same as in Example 1.

On trouve les résultats suivants :

Figure imgb0018
The following results are found:
Figure imgb0018

On décèle moins de 3 % (RT) de diméthoxy-1,2 benzène par chromatographie.Less than 3% (RT) of 1,2-dimethoxy benzene is detected by chromatography.

EXEMPLE-9EXAMPLE-9

Dans un tube de verre résistant à la pression, on introduit les réactifs suivants :

Figure imgb0019
On opère comme dans l'exemple 1.The following reagents are introduced into a pressure-resistant glass tube:
Figure imgb0019
 The procedure is as in Example 1.

On trouve les résultats suivants-:

Figure imgb0020
The following results are found:
Figure imgb0020

EXEMPLE 10EXAMPLE 10

Dans un tube de verre résistant à la pression, on introduit les réactifs suivants :

Figure imgb0021
The following reagents are introduced into a pressure-resistant glass tube:
Figure imgb0021

On opère comme dans l'exemple 1 mais l'essai est maintenu pendant 4 heures à 200°C. Le traitement du mélange réactionnel final et le dosage sont les mêmes que dans l'exemple 1 après addition d'eau.The procedure is as in Example 1 but the test is maintained for 4 hours at 200 ° C. Processing the final reaction mixture and dosing are the same as in Example 1 after addition of water.

On trouve les résultats suivants :

Figure imgb0022
The following results are found:
Figure imgb0022

On décèle moins de 5 % (RT) de diméthoxy-1,2 benzène par chromatographie.Less than 5% (RT) of 1,2-dimethoxy-benzene is detected by chromatography.

EXEMPLE 11EXAMPLE 11

Dans un tube de verre résistant à la pression, on introduit les réactifs suivants :

Figure imgb0023
On opère comme dans l'exemple 1, mais l'essai est maintenu pendant 4 i heures à 200°C. Le traitement du mélange final et le dosage sont les mêmes que dans l'exemple 1 après addition d'eau.The following reagents are introduced into a pressure-resistant glass tube:
Figure imgb0023
 The procedure is as in Example 1, but the test is maintained for 4 i hours at 200 ° C. The treatment of the final mixture and the dosage are the same as in Example 1 after addition of water.

On trouve les résultats suivants :

Figure imgb0024
The following results are found:
Figure imgb0024

On ne décèle pas de diméthoxy-1,2 benzène par chromatographie.1,2-dimethoxy-benzene is not detected by chromatography.

EXEMPLE 12EXAMPLE 12

Dans un tube de verre résistant à la pression, on introduit les réactifs suivants :

Figure imgb0025
On opère comme dans l'exemple 1.The following reagents are introduced into a pressure-resistant glass tube:
Figure imgb0025
 The procedure is as in Example 1.

On trouve les résultats suivants :

Figure imgb0026
The following results are found:
Figure imgb0026

On ne décèle pas de présence de crésols ou de méthylanisole.No cresols or methylanisole are detected.

EXEMPLE 13EXAMPLE 13

Dans un tube de verre résistant à la pression, on introduit les réactifs suivants :

Figure imgb0027
On opère comme dans l'exemple 1.In a pressure-resistant glass tube, the following reagents:
Figure imgb0027
 The procedure is as in Example 1.

On obtient les résultats suivants :

Figure imgb0028
The following results are obtained:
Figure imgb0028

EXEMPLE 14EXAMPLE 14

Dans un tube de verre résistant à la pression, on introduit les réactifs suivants :

Figure imgb0029
On opère comme dans l'exemple 1.The following reagents are introduced into a pressure-resistant glass tube:
Figure imgb0029
 The procedure is as in Example 1.

On obtient avec une sélectivité (RT) d'environ 95 %, le monoéthyléther de pyrocatéchol (guétol). Le taux de transformation du pyrocatéchol est voisin de 15 %.With a selectivity (RT) of about 95%, the pyrocatechol monoethyl ether (guetol) is obtained. The transformation rate of pyrocatechol is close to 15%.

La teneur en diéthoxy-1,2 benzène est inférieure à 2 %.The content of 1,2-diethoxybenzene is less than 2%.

EXEMPLE 15EXAMPLE 15

Dans un tube de verre résistant à la pression, on introduit les réactifs suivants :

Figure imgb0030
On opère comme dans l'exemple 1.The following reagents are introduced into a pressure-resistant glass tube:
Figure imgb0030
 The procedure is as in Example 1.

On obtient le monométhyléther de l'hydroquinone avec un rendement d'environ 95 %, le taux de transformation de l'hydroquinone étant de 10 %. On note l'absence presque totale de diméthoxy-1,4 benzène (quantité inférieure à 2 %).The monomethyl ether of hydroquinone is obtained with a yield of approximately 95%, the conversion rate of hydroquinone being 10%. The almost complete absence of 1,4-dimethoxy benzene (less than 2%) is noted.

EXEMPLE 16EXAMPLE 16

Dans un tube de verre résistant à la pression, on introduit les réactifs suivants :

Figure imgb0031
On opère comme dans l'exemple 1. Le traitement du mélange réactionnel final et les dosages sont effectués par chromatographie gaz/liquide et par chromatographie liquide.The following reagents are introduced into a pressure-resistant glass tube:
Figure imgb0031
 The procedure is as in Example 1. The treatment of the final reaction mixture and the assays are carried out by gas / liquid chromatography and by liquid chromatography.

0n trouve les résultats suivants :

Figure imgb0032
The following results are found:
Figure imgb0032

EXEMPLE 17EXAMPLE 17

Dans un tube de verre résistant à la pression, on introduit les réactifs suivants :

Figure imgb0033
On opère comme dans l'exemple 1. Le traitement du mélange réactionnel final et les dosages sont effectués par chromatographie gaz/liquide et par chromatographie liquide.The following reagents are introduced into a pressure-resistant glass tube:
Figure imgb0033
 The procedure is as in Example 1. The treatment of the final reaction mixture and the assays are carried out by gas / liquid chromatography and by liquid chromatography.

On trouve les résultats suivants :

Figure imgb0034
The following results are found:
Figure imgb0034

EXEMPLE 18EXAMPLE 18

Dans un tube de verre résistant à la pression, on introduit les réactifs suivants :

Figure imgb0035
On opère comme dans l'exemple 1. Le traitement du mélange réactionnel final et les dosages sont effectués par chromatographie gaz/liquide et par chromatographie liquide.The following reagents are introduced into a pressure-resistant glass tube:
Figure imgb0035
 The procedure is as in Example 1. The treatment of the final reaction mixture and the assays are carried out by gas / liquid chromatography and by liquid chromatography.

0n trouve les résultats suivants :

Figure imgb0036
The following results are found:
Figure imgb0036

ESSAIS COMPARATIFS :COMPARATIVE TESTS: Essai A :Test A:

Dans un tube de verre résistant à la pression on introduit les réactifs suivants :

Figure imgb0037
The following reagents are introduced into a pressure-resistant glass tube:
Figure imgb0037

Le tube est scellé, puis on chauffe à 210°C sous agitation et on maintient à cette température pendant 5 h 30 mn.The tube is sealed, then heated to 210 ° C. with stirring and kept at this temperature for 5 h 30 min.

Après refroidissement on dose le mélange réactionnel final par chromatographie.After cooling, the final reaction mixture is assayed by chromatography.

On trouve les résultats suivants :

Figure imgb0038
The following results are found:
Figure imgb0038

On n'observe pas de sélectivité en monoéther.No selectivity for monoether is observed.

Essai B :Test B:

Dans un tube de verre résistant à la pression on introduit les réactifs suivants :

Figure imgb0039
In a pressure-resistant glass tube, the following reagents:
Figure imgb0039

On effectue l'essai dans les mêmes conditions que l'essai A et le mélange final est dosé comme précédemment.The test is carried out under the same conditions as test A and the final mixture is dosed as above.

On trouve les résultats suivants :

Figure imgb0040
The following results are found:
Figure imgb0040

On n'observe pas de sélectivité en monoéther.No selectivity for monoether is observed.

Essai C :Test C:

Dans un tube de verre résistant à la pression on introduit les réactifs suivants :

Figure imgb0041
The following reagents are introduced into a pressure-resistant glass tube:
Figure imgb0041

On effectue l'essai dans les mêmes conditions que l'essai A, mais la durée de maintien à 210°C est de 5 heures. Le traitement consiste dans l'extraction des composés organiques par l'éther isopropylique. On dose la solution organique obtenue par chromatographie.The test is carried out under the same conditions as test A, but the holding time at 210 ° C. is 5 hours. The treatment consists in the extraction of organic compounds with isopropyl ether. The organic solution obtained is assayed by chromatography.

On trouve les résultats suivants :

Figure imgb0042
The following results are found:
Figure imgb0042

On n'observe pas de sélectivité en monoéther.No selectivity for monoether is observed.

Claims (15)

1°) Procédé d'éthérification d'une fonction phénolique de composé de formule générale (I) :
Figure imgb0043
dans laquelle : - Ar représente un radical aromatique constitué par un cycle benzénique ou par plusieurs cycles benzéniques orthocondensés ou ortho- et péricondensés, - les substituants R, identiques ou différents, représentent un groupement hydroxyle, un radical alkyle linéaire ou ramifié ayant de 1 à 6 atomes de carbone, un radical alkényle linéaire ou ramifié ayant 2 à 6 atomes de carbone, un radical phényle éventuellement substitué, un radical cycloalkyle éventuellement substitué, un radical phénylalkyle dans lequel la chaîne aliphatique comporte 1 à 4 atomes de carbone, un radical cycloalkylalkyle dans lequel la chaîne aliphatique comporte de 1 à 4 atomes de carbone, un atome d'halogène, un groupement nitro, un groupement amine, un groupement aldéhyde, un groupement nitrile, - n est un nombre de 0 à 5, par réaction avec un agent d'éthérification choisi dans le groupe constitué par les carboxylates d'alkyle, le radical alkyle linéaire ou ramifié ayant 1 à 6 atomes de carbone, les carboxylates d'alkényle, le radical alkényle linéaire ou ramifié ayant 3 à 6 atomes de carbone et les composés susceptibles de former de tels carboxylates, caractérisé en ce que l'on opère en présence d'un sel d'acide carboxylique. 1 °) Process for the etherification of a phenolic function of a compound of general formula (I):
Figure imgb0043
 in which : Ar represents an aromatic radical constituted by a benzene cycle or by several orthocondensed or ortho- and pericondensed benzene cycles, the substituents R, which may be identical or different, represent a hydroxyl group, a linear or branched alkyl radical having from 1 to 6 carbon atoms, a linear or branched alkenyl radical having 2 to 6 carbon atoms, an optionally substituted phenyl radical, a optionally substituted cycloalkyl radical, a phenylalkyl radical in which the aliphatic chain contains 1 to 4 carbon atoms, a cycloalkylalkyl radical in which the aliphatic chain contains from 1 to 4 carbon atoms, a halogen atom, a nitro group, a group amine, an aldehyde group, a nitrile group, n is a number from 0 to 5, by reaction with an etherification agent chosen from the group consisting of alkyl carboxylates, the linear or branched alkyl radical having 1 to 6 carbon atoms, alkenyl carboxylates, the linear or branched alkenyl radical having 3 to 6 carbon atoms and the compounds capable of forming such carboxylates, characterized in that one operates in the presence of a carboxylic acid salt. 2°) Procédé selon la revendication 1, caractérisé en ce qu'il est appliqué à un composé de formule (I) dans laquelle : - le radical Ar correspond au benzène, au naphtalène, à l'anthracène ou au phénanthrène - les substituants R, identiques ou différents, représentent un groupement hydroxyle, un radical alkyle linéaire ou ramifié ayant de 1 à 4 atomes de carbone, un radical alkényle linéaire ou ramifié ayant 2 à 4 atomes de carbone, un radical phényle éventuellement substitué, un radical cyclohexyle éventuellement substitué, un radical phénylalkyle dans lequel la chaîne aliphatique comporte 1 à 3 atomes de carbone, un radical cyclohexylalkyle dans lequel la chaîne aliphatique comporte 1 à 3 atomes de carbone, un atome de chlore, un atome de brome ou un groupement nitro, - n est un nombre entier de 0 à 3. 2) Method according to claim 1, characterized in that it is applied to a compound of formula (I) in which: - the radical Ar corresponds to benzene, naphthalene, anthracene or phenanthrene - the substituents R, identical or different, represent a hydroxyl group, a linear or branched alkyl radical having from 1 to 4 carbon atoms, a linear or branched alkenyl radical having 2 to 4 carbon atoms, an optionally substituted phenyl radical, an optionally substituted cyclohexyl radical, a phenylalkyl radical in which the aliphatic chain contains 1 to 3 carbon atoms, a cyclohexylalkyl radical in which the aliphatic chain contains 1 to 3 carbon atoms, a chlorine atom, a bromine atom or a nitro group, - n is an integer from 0 to 3. 3°) Procédé selon l'une des revendications 1 et 2, caractérisé en ce qu'il est appliqué au phénol, au naphtol-1, au naphtol-2, au méthyl-2 phénol, au méthyl-3 phénol, au méthyl-4 phénol, aux monochlorophénols, aux dichlorophénols, au monoéthylphénols, au mononitrophénols, au pyrocatéchol, au résorcinol,à l'hydroquinone, au dihydroxy-1,2 naphtalène, au dihydroxy-1,3 naphtalène, au dihydroxy-1,4 naphtalène, au dihydroxy-1,5 naphtalène, au dihydroxy-1,6 naphtalène, au dihydroxy-1,7 naphtalène, au dihydroxy-1,8 naphtalène, au dihydroxy-2,3 naphtalène, au dihydroxy-2,6 naphtalène, au dihydroxy-2,7 naphtalène.3 °) Method according to one of claims 1 and 2, characterized in that it is applied to phenol, naphthol-1, naphthol-2, 2-methylphenol, 3-methylphenol, methyl- 4 phenol, monochlorophenols, dichlorophenols, monoethylphenols, mononitrophenols, pyrocatechol, resorcinol, hydroquinone, 1,2-dihydroxy naphthalene, 1,3-dihydroxy naphthalene, 1,4-dihydroxy naphthalene, with dihydroxy-1,5 naphthalene, with dihydroxy-1,6 naphthalene, with dihydroxy-1,7 naphthalene, with dihydroxy-1,8 naphthalene, with dihydroxy-2,3 naphthalene, with dihydroxy-2,6 naphthalene, with dihydroxy -2.7 naphthalene. 4°) Procédé selon l'une quelconque des revendications 1 à 3, caractérisé en ce que l'agent d'éthérification est choisi parmi les esters : - des acides carboxyliques aliphatiques saturés ou insaturés monofonctionnels comportant notamment 2 à 18 atomes de carbone ou polyfonctionnels comportant notamment 3 à 18 atomes de carbone, - des acides aromatiques mono- ou polyfonctionnels, - des acides arylaliphatiques mono- ou polyfonctionnels, - ou des acides cycloaliphatiques mono- ou polyfonctionnels avec des alcools tels que le méthanol, l'éthanol, le n-propanol, l'isopropanol, le butanol-l, le butanol-2, le tertiobutanol, le propène-2 ol-l, le méthyl-2 propène-2 ol-1, le butène-2 ol-1, le butène-3 ol-l, le butène-3 ol-2. 4 °) Method according to any one of claims 1 to 3, characterized in that the etherification agent is chosen from esters: - monofunctional saturated or unsaturated aliphatic carboxylic acids comprising in particular 2 to 18 carbon atoms or polyfunctional comprising in particular 3 to 18 carbon atoms, - mono- or polyfunctional aromatic acids, - mono- or polyfunctional arylaliphatic acids, - or mono- or polyfunctional cycloaliphatic acids with alcohols such as methanol, ethanol, n-propanol, isopropanol, butanol-1, butanol-2, tertiobutanol, propene-2 ol-1 , 2-methyl-propene-2 ol-1, butene-2 ol-1, butene-3 ol-1, butene-3 ol-2. 5°) Procédé selon l'une quelconque des revendications 1 à 3, caractérisé en ce que l'agent d'éthérification est constitué par un mélange : - d'un alcool tel que le méthanol, l'éthanol, le n-propanol, l'isopropanol, le butanol-1, le butanol-2, le tertiobutanol, le propène-2 ol-l, le méthyl-2 propène-2 ol-l, le butène-2 ol-l, le butène-3 ol-1, le butène-3 ol-2. - et d'un acide carboxylique tel que : - un acide carboxylique aliphatique saturé ou insaturé monofonctionnel comportant notamment 2 à 18 atomes de carbone ou polyfonctionnel comportant notamment 3 à 18 atomes de carbone, - un acide aromatique mono- ou polyfonctionnel, - un acide arylaliphatique mono- ou polyfonctionnel, - ou un acide cycloaliphatique mono- ou polyfonctionnel. 5 °) Process according to any one of Claims 1 to 3, characterized in that the etherification agent consists of a mixture: - an alcohol such as methanol, ethanol, n-propanol, isopropanol, butanol-1, butanol-2, tertiobutanol, propene-2 ol-1, 2-methyl-propene-2 ol-1, butene-2 ol-1, butene-3 ol-1, butene-3 ol-2. - and a carboxylic acid such as: - a monofunctional saturated or unsaturated aliphatic carboxylic acid comprising in particular 2 to 18 carbon atoms or polyfunctional comprising in particular 3 to 18 carbon atoms, - a mono- or polyfunctional aromatic acid, - a mono- or polyfunctional arylaliphatic acid, - or a mono- or polyfunctional cycloaliphatic acid. 6°) Procédé selon la revendication 5, caractérisé en ce que le rapport molaire alcool/acide carboxylique est compris entre 0,02 et 50 et de préférence entre 0,1 et 40.6 °) Method according to claim 5, characterized in that the alcohol / carboxylic acid molar ratio is between 0.02 and 50 and preferably between 0.1 and 40. 7°) Procédé selon l'une des revendications 4 à 6, caractérisé en ce que l'acide carboxylique entrant dans la composition de l'agent d'éthérification est un acide aliphatique saturé mono- ou difonctionnel ayant de 2 à 6 atomes de carbone, l'acide benzoïque ou un des acides ortho- méta- et téréphtaliques.7 °) Method according to one of claims 4 to 6, characterized in that the carboxylic acid used in the composition of the etherification agent is a saturated aliphatic acid mono- or difunctional having from 2 to 6 carbon atoms , benzoic acid or one of the ortho-meta and terephthalic acids. 8°) Procédé selon l'une quelconque des revendications 1 à 7, caractérisé en ce que le sel d'acide carboxylique utilisé est un carboxylate de métal alcalin, d'ammonium ou de métal alcalino-terreux, et de préférence de métal alcalin.8 °) A method according to any one of claims 1 to 7, characterized in that the carboxylic acid salt used is an alkali metal, ammonium or alkaline earth metal carboxylate, and preferably alkali metal. 9°) Procédé selon l'une quelconque des revendications 1 à 8, caractérisé en ce que le sel d'acide carboxylique utilisé est un sel d'un acide aliphatique saturé mono- ou difonctionnel ayant 2 à 6 atomes de , de l'acide benzoïque ou de l'un des acides ortho-, méta- et réphtaliques.9 °) A method according to any one of claims 1 to 8, characterized in that the carboxylic acid salt used is a salt of a saturated aliphatic acid mono- or difunctional having 2 to 6 atoms of, the acid benzoic or one of the ortho-, meta- and rephthalic acids. 100) Procédé selon l'une quelconque des revendications 1 à 9, caractérisé en ce que l'on opère en présence d'eau.10 0 ) Method according to any one of claims 1 to 9, characterized in that one operates in the presence of water. 110) Procédé selon la revendication 10, caractérisé en ce que l'eau représente de 1 % à 95 % en volume du milieu réactionnel liquide et de préférence de 20 % à 80 %.11 0 ) Process according to claim 10, characterized in that water represents from 1% to 95% by volume of the liquid reaction medium and preferably from 20% to 80%. 12°) Procédé selon l'une des revendications 1 à 3 et 5 et 6, caractérisé en ce que l'on utilise un diacide carboxylique dont une fonction acide est libre et l'autre est salifiée.1 2 °) Method according to one of claims 1 to 3 and 5 and 6, characterized in that one uses a dicarboxylic acid of which one acid function is free and the other is salified. 13°) Procédé selon l'une quelconque des revendications 1 à 12, caractérisé en ce que l'on opère à une température située entre 150°C et 350°C, et de préférence entre 220°C et 300°C.13 °) Method according to any one of claims 1 to 12, characterized in that one operates at a temperature between 150 ° C and 350 ° C, and preferably between 220 ° C and 300 ° C. 14°) Procédé selon l'une quelconque des revendications 1 à 13, caractérisé en ce que l'on utilise un rapport molaire ester ou alcool entrant dans la composition de l'agent d'éthérification/composé phénolique égal ou supérieur à 0,5, et de préférence égal ou supérieur à 1.14 °) Process according to any one of claims 1 to 13, characterized in that an ester or alcohol molar ratio used in the composition of the etherification agent / phenolic compound equal to or greater than 0.5 is used. , and preferably equal to or greater than 1. 15°) Procédé l'une quelconque des revendications 1 à 14, caractérisé en ce que les éthers formés se trouvant dans la masse réactionnelle finale sont extraits par le cyclohexane.15 °) Process any one of claims 1 to 14, characterized in that the ethers formed being in the final reaction mass are extracted with cyclohexane.
EP81420047A 1980-03-31 1981-03-30 Process for the etherification of phenols Expired EP0037353B1 (en)

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FR8007628A FR2479189A1 (en) 1980-03-31 1980-03-31 PHENOLS ETHERIFICATION PROCESS
FR8007628 1980-03-31

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2513632A2 (en) * 1980-08-25 1983-04-01 Rhone Poulenc Spec Chim Etherification of phenolic cpds. with alcohol(s) - in presence of carboxylate salt and metal iodide, giving faster reaction
FR2513633A1 (en) * 1981-09-29 1983-04-01 Rhone Poulenc Spec Chim PHENOLS ETHERIFICATION PROCESS
EP0425974A2 (en) * 1989-11-03 1991-05-08 BASF Aktiengesellschaft Process for the preparation and purification of 2-hydroxy-4-(2'-hydroxy-ethoxy)-phenylarylketones

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0000162A1 (en) * 1977-06-28 1979-01-10 BASF Aktiengesellschaft Method for preparing aralkyl and alkyl phenol ethers

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Publication number Priority date Publication date Assignee Title
US3927118A (en) * 1973-12-21 1975-12-16 Crown Zellerbach Corp Process for monoetherification of polyhydric benzenes

Patent Citations (1)

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Publication number Priority date Publication date Assignee Title
EP0000162A1 (en) * 1977-06-28 1979-01-10 BASF Aktiengesellschaft Method for preparing aralkyl and alkyl phenol ethers

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Bulletin of the Chemical Society of Japan, Vol. 45, 1972 T. KITO et al.: "O-Alkylation of Phenols by Esters" pages 3490-3492 * en entier * *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2513632A2 (en) * 1980-08-25 1983-04-01 Rhone Poulenc Spec Chim Etherification of phenolic cpds. with alcohol(s) - in presence of carboxylate salt and metal iodide, giving faster reaction
FR2513633A1 (en) * 1981-09-29 1983-04-01 Rhone Poulenc Spec Chim PHENOLS ETHERIFICATION PROCESS
EP0076221A1 (en) * 1981-09-29 1983-04-06 Rhone-Poulenc Specialites Chimiques Process for the etherification of phenols
EP0425974A2 (en) * 1989-11-03 1991-05-08 BASF Aktiengesellschaft Process for the preparation and purification of 2-hydroxy-4-(2'-hydroxy-ethoxy)-phenylarylketones
EP0425974A3 (en) * 1989-11-03 1991-07-03 Basf Aktiengesellschaft Process for the preparation and purification of 2-hydroxy-4-(2'-hydroxy-ethoxy)-phenylarylketones

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FR2479189B3 (en) 1982-12-10
FR2479189A1 (en) 1981-10-02

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